Indexing work fixture



July 1954 E. E. TESSNEER ET AL INDEXING WORK FIXTURE 5 Sheets-Sheet 1Filed April 27, 1951 INVENTORS,

T? L a ATTORNEY J y 1954 E. E. TESSNEER ET AL INDEXING WORK FIXTURE 5Sheets-Sheet 2 Filed April 27, 1951 1N EITITORO:

ATTORNEY J y 20, 1954 E. E. TEssNEER ET AL 2,684,

INDEXING WORK FIXTURE Filed April 27, 1951 5 Sheets-Sheet 3 IE6.5 M

g INVENTfi 7 1 mm,

D I 111.. P M

ATTORNEY,

J y 1954 E. E. TESSNEER ETAL INDEXING WORK FIXTURE 5 Sheets-Sheet 4Filed April 2'7, 1951 KO INVENTORY ATTORNEYS y 20, 1954 'E. E. TESSNEERETAL I 2,684,018 INDEXING WORK FIXTURE 5 Sheets-Sheet 5 ZNVENTORS.

ATTORNEYS,

Patented July 20, 1954 UNITED STATES PATENT GFFICE INDEXING WORK FIXTUREEzra E. Tessneer and Allen D. Gunderson, Racine, Wis., assignors toGeorge Gorton Machine 00., a corporation of Wisconsin Application April27, 1951, Serial No. 223,252

1 14 Claims.

This invention relates to indexing work fixtures of the typesparticularly adapted, although not limited, to mounting on the worktable of an engraving or the like machine tool; and the nature andobjects of the invention will be readily understood by those skilled inthe art in the light of the following explanation and detaileddescription of a preferred embodiment or mechanical expression of ourinvention, from among various other embodiments, expressions, forms,designs, constructions and combinations of which the invention iscapable within the broad spirit and scope thereof as defined by theappended claims.

It is a primary object of our invention to provide an indexing workfixture by which a work piece may be indexed with precision successivelyto predetermined positions of index relative to a tool adapted tooperate upon the work piece.

Another object is to provide such an indexing work fixture as a. unitaryorganization for removable mounting as a unit on the work table of amachine tool or other support structure.

Another object is to provide such a fixture which will adjust itselfautomatically for indexing with precision of positioning throughsuccessive positions or" index having different spacings therebetween.

A further object is to provide a work indexing fixture adapted for themounting thereon interchangeably of any one of a plurality of indexcontrolling members each of which provides for indexing by the fixturethrough a series of indexing positions having spacings therebetweendifferent from the spacings between the indexing positions provided forby the other of said con trolling members.

A further object is to provide for operator controlled, poweredoperation of such an indexing fixture automatically through a cycle ofindexing from one position of index to the next position of index.

Another object is to provide such an indexing fixture in which thefixture is releasably looked automatically in each position of index andis unlocked automatically for indexing from one position to the next.

Another object is to provide an indexing fixture indexible step by stepthrough a succession of index positions by an indexing mechanismoperable through an index stroke, and a return stroke the length ofwhich is determined automatically by the spacing between successivepositions of index.

Another object is to provide an efiicient powered operating system andelectrical control circuits therefor for operating an indexing workfixture through an indexing cycle of movement from one position of indexto the next position under the control of an operator.

And a further object is to provide such an indexing fixture and itsoperating system as a unit particularly adapted for removable mountingon the Work table of a multiple spindle engraving machine for engravingsimultaneously a plurality of work pieces mounted on the indcxingfixture as such Work pieces are moved by said fixture to successivepositions of index.

With the foregoing and various other objects, features and results inView which Will be readily apparent from the following detaileddescription and explanation, our invention consists in certain novelfeatures in design and construction of parts and elements and incombinations and sub-combinations thereof, all as will be moreparticularly referred to hereinafter.

Referring to the accompanying drawings in which similar referencecharacters refer to corresponding parts and elements throughout theseveral figures thereof:

Fig. 1 is a perspective View of a multiple spindle engraving machine ofthe tracer controlled, pantographic type having mounted thereon a workindexing fixture organization of our invention, a plurality of Workpieces being shown in mounted position on the work fixture.

Fig. 2 is a view in top plan of the indexing work fixture of Fig. 1, thework mounting table thereof being shown in position for the start ofindexing movements thereof through a series of indexing positions.

Fig. 3 is a view in top plan of the support base or bed of the Workindexing fixture of Fig. 2, with the fixture table removed to show intop plan the indexing pawl and carrier bar therefor of the indexingmechanism.

Fig. 4 is a vertical section taken as on the line 6-4 of Fig. 3.

Fig. 5 is a View in front elevation of the work fixture of Fig. 2, thefixture being shown as though removed from the work table of theengraving machine of Fig. 1.

Fig. 6 is a transverse vertical section taken as on the line 'E6 of Fig.2.

Fig. 7 is a vertical section taken as on the line l-i of Fig. 2.

Fig. 8 is a vertical section taken as on the line 8-B of Fig. 2.

Fig. 9 is a fragmentary, enlarged detailed view of an indexing barshowing the inner end, transverse head thereof and several of the teethof the series of indexing teeth thereon.

Fig. 10 is a view similar to Fig. 9, but of an- 3 other indexing barhaving a series of teeth thereon of different spacing therebetween thanthe spacing between the teeth of the bar of Fig. 9.

Fig. 11 is a detail, enlarged view in top plan showing the indexing pawland the pawl carrier and indexing bar therefor at the completion of anindexing stroke.

Fig. 12 is a view similar to Fig. 11, but showing the pawl in positionriding over the end of a tooth on the return stroke of the pawl and itscarrier bar.

Fig. 13 is a view similar to Fig. 12 but showing the pawl in positionengaging in a notch of the indexing bar at the end of the return strokeand with the tail of the pawl engaged with the switch for effecting theindexing stroke of the pawl and its carrier bar.

Fig. 14 is a diagrammatic view of the air cylinder units and controllingair valves with the compressed air supply system therefor, and of theair valve controlling solenoids and their circuits with the controllingswitches therefor in such circuits.

Fig. 15 is an end elevation taken from the left hand end of the workindexing fixture of Fig. 2.

An indexing work fixture of our invention has found particular utilitywith a multiple spindle engraving machine of the tracer controlledpantographic type for engraving various symbols, indicia and the likesimultaneously on a plurality of work pieces. Hence, we have selected asan example form for purposes of explanation, an indexing work fixtureunit embodying our invention of a form for use with such types ofmultiple spindle engraving machines by which the work pieces may beindexed automatically under the control of the operator to successivepositions of index for engraving at spaced intervals along the workpieces. Iowever, by the illustrated form of indexing work fixture unitof the selected example, we do not intend or desire to limit ourinvention to such particular form or to use with engraving machines ofthe illustrated type. The various features of an indexing work fixtureof our invention, including that feature by which the indexing mechanismadjusts itself automatically to the spacings between successivepositions of index of diiferent series of index spacings, and thatfeature by which different indexing control members are utilized forobtaining the spacing between different series of index spacings, arereadily adaptable to embodiment in various other forms, designs andarrangements for work piece indexing with. various types of machinetools, as will be more fully explained. in detail hereinafter.

A multiple spindle engraving machine of a type for which the selectedexample form of the invention is particularly designed, is illustratedin Fig. 1 of the accompanying drawings. Such machine includes asupporting frame structure which may be in the form of a vertical columnC, a portion only of which is shown. On this column (3' there is mounteda work table organization W of the so-called duplicator type in whichthe table W is mounted in horizontally disposed position for universallateral movements in a horizontal plane. Such a duplicator table may,for example, be of the general type dis closed in the U. S. Patent2,005,696, dated June 18, 1935, to which patent reference may be had foran understanding of the operation of the work, table W. The, column Cmounts or provides at the upper end thereof to the rear of work table W,a forwardly extended overarm A which mounts on and across the forwardside thereof, a series of vertically disposed, motorized spindle unitsS, there being six (6) of such units in the illustrated machine. Theseunits S are positioned by overarm A above work table W and each unitincludes a rotary spindle S which is formed at the lower end thereof todetachably mount therein a rotary engraving tool E.

At the right hand, forward side of work table W there is supported fromcolumn structure C a pattern or copy table M, which in this instancehappens to be of the circular type mounted for rotation in a horizontalplane about a vertical axis. A pantograph unit P is pivotally hung at Pfrom the frame structure of the machine at the right hand side of worktable W and is in turn pivotally coupled with the adjacent, right end ofthe work table W. Pantograph unit P includes a forwardly extended tracerarm T which mounts at its forward, free end a vertically disposed tracerunit T. The tracer unit T is located above the side of copy table Madjacent work table W and is adapted to be manually moved universallylaterally by an operator in tracing a suitable master M mounted on theupper side of the copy table and moved by that table to position belowthe tracer unit. Thus, as will be readily understood by those familiarwith this general type of tracer controlled, panto graphic engravingmachine, movements laterally of the tracer unit T over a master M totrace or scan the design thereof, are transmitted by the pantograph P tothe work table W as movements laterally of the work table W through ahorizontal plane in accurately scaled reduction of the movements of thetracer unit T in scan: ning or tracing the master.

In the operation of the example machine of Fig. l to engrave on suitablework pieces, an accurately scaled reproduction of the design presentedby a master M, the work is secured on table W in positions below thespindle units and the copy table M is then rotated to position thedesired master M on the table below the trace unit T. The operator thenscans or traces the design on master M with the tracer T, and in so.doing the tracer arm '1 actuates the pantograph P which in ttuhtransmits to the work table W the exact movements of tracer T but inaccurately scaled reduction of the tracer movements. Such movements ofwork table W will move the work pieces thereon relative to the laterallyfixed cutting tools E, respectively so that these tools engravesimultaneously on the work pieces reproduction of the design on master Mbeing traced by tracer T.

In the form of indexing work fixture of the selected example of ourinvention, such fixture being identified generally by the referencecharacter F, the fixture is comprised of a unitary organization which isdetachably mounted and secured in operative position on the work table Wfor universal lateral movements as a unit therewith as such table ismoved by the pantograph P in tracing a master. In this example theindexing work fixture unit F comprises a bed or base plate 10 and a workpiece mounting, in dexable table 20 slidably mounted and confinedthereon for movements in either direction along a straight-line pathtransversely thereof. The bed or base plate I0. is of generallyrectangular plan form and is adapted to be detachably mounted andsecured in fixed position on and over the work table W for universallateral movements therewith. Bed I 0, may be removably secured andattached in position on work table W by the usual securing bolts l 1adapted to be received in the usual T-slots formed in the upper side ofa work table W.

The indexable work table 20 of the work fixture unit F is of rectangularplan form and provid-es, in this instance, a fiat upper surface 20a forclamping thereon a plurality of work pieces R in positions to be locatedbelow the engraving cutters E, respectively, of spindle units S for operative cutting or engraving engagement of those cutters with the workpieces. As the example machine is provided with six (6) spindle units S,the work table 283 is adapted to mount thereon six (6) work pieces forsimultaneous engraving operations by the engraving cutters E of thespindle units 5, respectively. However, any lesser number of work piecesmay be mounted on work table it for engraving operations thereon by asimilar number of the spindle units S. The fixture work table 29 is inthis example designed and arranged for movements in either directionalong a straight line path disposed in and out relative to the machine,that is from front to rear thereof, in order to permit of engraving aseries of designs or indicia spaced apart at intervals along thelongitudinal lengths of the work pieces R which are secured in positionsdisposed transversely across the fixture table, that is from front torear of the machine, as will be clear by reference to Fig. 1. Workpieces B. may be removably secured in position on the table 29 by anysuitable clamps or the like, with the work pieces being spaced apart ina parallelism beneath and aligned vertically with the cutters E.

in the example embodiment the fixture work table it has a width, that isa front to rear dimension, less than the width or front to reardimension of the bed ill. The bed It in this instance has a width orfront to rear dimension greater than the front to rear dimension of theuniversally laterally movable work table W of the machine, so that bedE0 in mounted position on work table W extends a distance substantiallyforwardly beyond the forward edge of table W. The fixture table 26 inposition at the start of an indexing cycle, is displaced forwardly onbed iii to a position with its forward edge located in or in closeproximity to the vertical plane passing through the forward edge of bedI0. This starting position of fixture work table H3 is shown in Pig. 2.From this starting position table 2% progressively moved rearwardly stepby step through a succession of index positions until it reaches aposition at the conclusion of the indexing cycle in which its rear edgeis adjacent the rear edge of bed ill. Such position of fixture table Zilis shown in Fig. l of the drawings.

The bed it is formed or provided on the upper side thereof with thespaced, parallel slides or rails it and it disposed transverselythereacross and extending from front to rear thereof to form a dovetailslide defining the straight line path along which the fixture work table20 is to be moved in either direction, that is from front to rearrelative to the machine. The fixture work table 2c is provided at theunderside thereof with dovetail slideway 2| cut or otherwise formedtherein to extend from front to rear thereof. slideway it provides alongthe opposite, longitudinal sides thereof the spaced, parallel bearingsurfaces 2 la and 2 lb for sliding bearing engagement with the oppositeundercut bearing surfaces [Ed and I ia, respectively, provided along theouter sides of the spaced rails l2 and It on bed [0, as clearly shown byFigs. 6, '7 and 8. Fixture table 20 is slidably mounted and confined onthe bed in by the slides l2 and 14 which are received and slidablyfitted into the dovetail slideway 2!, so that the table is then freelyslidable on and along but constrained to a straight-line path ofmovement transversely across bed Ill, in and out relative to themachine.

In this instance, a gib 22 is provided mounted in position between theundercut bearing surface in of slide l2 and the undercut surface 2 id ofthe dovetail slideway 2|. The inner surface 22a of this gib 22 providesthe bearing surface for slidable engagement with and along bearingsurface i2a, as will be clear by reference to Figs. 6, 7 and 8. The gib22 is coupled with fixture table it for movements therewith as a unitarycomponent, being held against any movements longitudinally relative tothe table but being mounted for play or slight movements laterally ineither direction relative to the table and toward or from the slidebearing surface 12a. This mounting of gib 22 may be effected by anarrangement of spaced pins 23 mounted in and extending through ta le 29with their inner ends projected beyond undercut surface 21a of slideway2i and being slidably received in suitable bores 22b respectively formedin gib 22. If desired suitable adjustment screws 24 may be provided inand extended through table it with their inner ends projected beyondunder- 2 la and being received in suitable recesses 26a in the adjacentside of the gib to limit outward movement of the gib by abutment againstthe inner ends walls of the recesses. Thus, the gib has sufficient playlaterally between surface tin of slideway 2i and surface lid of slideway12 to permit of lateral displacement thereof to from a locking positionclamped against surface 52a. to thereby releasably lock table it againstmovements on and relative to bed It.

We provide indexing mechanism under the control of an operator forindexing the fixture work table 29 from its starting position at theforward side of bed It, inwardly over and across the bed step by stepthrough successive positions of index. In this manner the work pieces Bmay be indexed inwardly or rearwardly across bed it relative to therotary engraving tools E of the laterally fixed spindle units S of themachine to thereby enable the cutters E to engrave at spaced intervalsalong the work pieces R a scaled reduction of the designs of a master Mselected by the operator for reproduction. In any indexed position ofthe fixture table 20 on bed in, the bed 10 and table 20 are universallylaterally movable as a unit with the work table W relative to laterallyfixed cutters E under the control of tracer T and pantograph P.

The indexing mechanism includes an indexing bar or member 30 which isremovably mounted and secured in the underside of fixture table 29 inposition disposed longitudinally of and through the slideway 2!. In thisparticular adaptation of our invention, the indexing bar 39 is providedalong its upper side with a dovetail rib 3| which extends from end toend of the bar. A dovetail groove 25 is provided in the fixture table2i! at the underside thereof within the slideway 2i, with this grooveopening along its lower side into the slideway 2i and at its oppositefront and rear ends opening through the front and rear edge walls,respectively, of the fixture table. The groove 25 is positioned offsetto the right from the longitudinal center of slideway 2i, so that, inmounted position of fixture table 20 it 7 is located along and adjacentthe slide rail IA of the bed it. An indexing bar'3il is removablymounted in position on fixture table by inserting the dovetail rib 3|thereof into the dovetail groove and then sliding the bar rearwardlyuntil the inner or rear end thereof is substantially flush with the rearedge surface of the fixture table 20. The indexing bar 3% has a widthfor the major portion of its length such that the outer vertical sidethereof has close operating clearance along the adjacent vertical edgesurface of slide rail [4, while the opposite inner side of the bar isdisposed approximately along the longitudinal center of slideway 2i. Thewidth of the rear or inner end portion of an indexing bar 39 isincreased by a laterally inwardly extended portion 3'! to therebyprovide an increased width transverse head 38 thereacross with theforward end wall of extension 37 providing a vertical, fiat abutmentsurface 31a and the head 33 providing across the rear end thereof avertical abutment surface 38a.

An indexing bar 3d is removably attached in mounted position by means ofa plate fixture 32 which is secured in vertically disposed positionagainst the rear edge of the fixture table 26, across and closing therear, open end of dovetail groove 25. Plate 32 may be secured inposition by suitable spaced machine screws 32a threaded into table 23.The plate 32 is provided with a transverse bore 34 therethrough locatedin position between screws 32a for axial alignment with an internallythreaded bore 35 in and opening through the rear surface 38a of the endhead 38 of the bar 38. An attachment screw St is provided for insertionthrough the bore 35 of the plate 32, and for threading up into bore 85to thereby draw the bar to and secure it in its mounted position withthe abutment surface 33a of head engaged against the adjacent verticalsurface of the attachment plate 32. Thus attached in mounted position atthe underside of table 23 within slideway 2 I, the indexing bar 32- isfixedly secured against movement or displacement relative to the tableand is movable therewith as a unit. An indexing bar 85 may be readilyremoved from mounted position by unscrewing the attachment screw 36 torelease the bar, and then drawing the bar outwardly until the dovetailrib 3! thereof is clear of groove 25 with the bar thus completelydetached and removed from the table 20.

An indexing bar of our invention, such as the bar 3% herein illustratedreferring now to Figs. 2 and 9, is provided along its inner, verticallongitudinal edge 30a with a series of indexing teeth Teeth id arespaced precise distances apart along the bar edge 36a and extendlaterally outwardly and horizontally on bar 39. The teeth 49 are formedand defined by notches 4| cut into the bar 36 through the bar edge 30athereof. Notches ll are so shaped as to form at the front or forwardside of each tooth 40 a vertically disposed surface 42 in a planeperpendicular to the longitudinal axis of the bar, and to form at therear side of each tooth a rearwardly and inwardly inclined or slopingsurface 3 which extends from the outer edge of that tooth to the innerend of the surface 42 at the forward side of the next adjacentrearwardly located tooth, as will be clear by reference to Fig. 9. Theinclined or sloping surface 3 at the rear of each tooth. is in thepresent example inclined at an angle of 45 to the longitudinal axis ofthe bar 30. With the bar 30 in mounted position, the teeth 46 thereofextend along the inner edge 30a of the bar with the most forwardlylocated tooth 48 of the series spaced inwardly a distance from the frontend of the bar and with the rearmost tooth 48 of the series spacedforwardly the width of a notch from the abutment Wall 31a of thehead-forming lateral extension 3? at the inner end of the bar.Obviously, any lesser number of teeth may be pro vided if desired havingthe spacing therebetween of the teeth 40 of the series thereof providedon bar 36 of the illustrated example.

An important feature of an indexing work fixture of our inventionresides in the provision of interchangeable indexing bars each havingthereon a series of indexing teeth having a different tooth spacingtherebetween. In carry ing out this feature we may, as in the presentexample, provide a plurality of indexing bars for interchangeablemounting on fixture table 23, with each bar having a difierent toothspacing, so that the fixture table 26 may be indexed to successive indexpositions spaced apart precisely in accordance with the tooth spacing ofthe particular indexing bar mounted on the table. The indexing bars,except for the number of teeth and the spacing therebetween, areidentical in design, construction and dimensions, that is in the presentexample, identical with the in dexing bar 39. For instance, we haveshown in Fig. 10 a portion of an indexing bar 35 which is identical withbar 30 except that adjacent indexing teeth 40' thereon with the notch41' therebetween are spaced apart a distance equal to approximatelyone-half (/2) of the distance or spacing between adjacent teeth Mi ofthe index ing bar 3!]. Thus, by removing bar 39 from mounted position onfixture table 29 and replacing it with the indexing bar 3&3, theindexing fixture table 23 will be indexed step by step throughsuccessive positions of index which are spaced apart precisely inaccordance with the spacing of the teeth fill, that is, a distancebetween index positions of approximately one-half the distance betweenthe index positions for the table 25; when indexed by and under thecontrol of the indexing bar 30. These interchangeable indexing bars maybe provided with any desired nunber of teeth and tooth spacing for theseries of teeth of each bar, within the limits of course, of theindexing range of the particular indexing fixture unit with which thebars are to be used.

The step by step indexing of the fixture work table 20 is effectedthrough the medium of the indexing bar mounted thereon, such for exampleas the indexing bar 38, in operative association with an indexing pawl50 pivoted on a reciprocating slide or carrier bar 60. Carrier bar 69 ismounted on bed i G for engaging a tooth of the indexing bar on theindexing stroke of the carrier bar 68 and for positioning by that bar onits return stroke for engagement with an adjacent tooth by the nextindexing stroke of the carrier bar.

Referring now to Figs. 3, 6, '7 and 8, the bed if] is formed with aforwardly extended bracket forming extension ifia across theintermediate front portion thereof, and a groove or slideway BI isprovided in the bed 0 disposed transversely thereof between guideways l2and it. Slideway 9! extends forwardly to and opens through the forwardend of the bracket extension Hid. This slideway 6| is located along andadjacent guide rail I4 below the indexing bar 30 mounted on table 20,and is open at its upper side throughout its length and width. Theslideway 6! is of rectangular cross section with a width greater thanthe width of an indexing bar 39, so that the slideway extends throughoutits length a substantial distance inwardly beyond the inner toothed edge39a of the indexing bar it. The slideway 6! is parallel with guide railsi2 and is and with the straight line path of table movement defined bythose guideways. slideway 6! extends a distance inwardly or rearwardlyalong the bed between guide rails 12 and i l. slideway iii is closed atthe inner, rear end thereof by a transverse vertical wall provided bythe body of bed it which wall presents a vertical abutment surface 52across the inner end of the slideway in a plane perpendicular to thelongitudinal axis of the slideway. The pawl carrier bar it is ofrectangular cross section with a width to be slidably fitted andreceived in slideway iii and a thickness of depth such that the upperplanar surface Eda thereof lies in the plane of the bottom or lowersurface of the bed Id between guide rails i2 and Hi. Thus, the pawlcarrier bar 60 is mounted for reciprocation beneath and freelyindependently of the indexing bar 30, and has a width such that itextends throughout its length for a distance inwardly beyond and clearof the in dexing bar to present an unobstructed upper planar surfacealong the inner side of the indexing bar in the plane of the undersurface of the latter bar.

The pawl 50 is pivotally mounted on the upper side of carrier bar SE! ata location spaced inwardly a distance from the inner end thereof, forhorizontal rocking about a fixed pivot pin 55, toward and from the teeth49 along the adjacent edge 36a of the indexing bar 30. At its inner endthe pawl 5t provides the laterally inwardly projected tooth 52 foroperative engagement with the teeth db of the indexing bar. Paw] 50 isprovided with a forwardly extended, reduced width tail portion 53 andthe carrier bar ti: is provided with a recess or cut out portion 53which is extended inwardly through the inner side thereof beneath thetail 53 of pawl 53. Tail 53 is provided with a flange 5 depending fromthe inner side edge thereof, and a spring unit 55 is interposed betweenthe depending ilange 54 and the carrier bar til at the inner side ofrecess $3. This spring 55 is confined under compression between tailflange 5d and the carrier bar fill and acts to continuously bias thetail 53 outwardly from bar Gil to maintain the tooth 52 and pawl 5iswung into operative indexing engagement in a notch li between adjacentteeth 48 of the series of teeth on the indexing bar 39.

The pawl carrier (it on the indexing strokes thereof inwardly throughslideway ti, is limited by the fixed stop provided by the abutmentsurface 52 across the inner end of the slideway which is positivelyengaged by the inner end of the carrier bar til at the conclusion ofeach indexing stroke of the bar. With the carrier bar 6E3 at the end ofan indexing stroke, the pawl 55) thereon has the tooth 52 engaged in anotch d! between adjacent teeth id of the indexing bar 3d, as shown inFigs. 2 and ll. When the carrier bar 65 is moved outwardly in slidewayti on its return stroke, tooth 52 of the pawl 50 rides upon the inclinedsurface at at the forward side of the notch ti and earns the pawl 5eoutwardly over the next forwardly adjacent tooth. As soon as tooth 52clears the index tooth at it snaps back into the next forwardly adjacentnotch 4! under the action of the biasing spring 55, The carrier bar stand its pawl 58 are then in position on the next indexing stroke thereofto effect index ing of the fixture table 29 to the next position ofindex, through engagement of the tooth 52 of pawl 50 against the surface22 at the forward side of the next inwardly adjacent tooth 40 While theindexing stroke of the carrier bar 65 has a fixed end limit, by animportant feature of our invention the end limit of outward movement ofthe carrier bar on its return stroke is variable automatically to adjusteach return stroke to the particular spacing between adjacent teeth onan indexing bar as will be referred to and explained in detailhereinafter.

The pawl carrier 66 is positively reciprocated on its rearward, indexingstrokes and on its forward, return strokes by an air cylinder and pistonunit it} which is mounted and secured in position at the underside ofbed It by a bracket structure H suitably attached to the bed. The aircylinder unit l9 is located, in this example, at the right-hand side ofbed It? adjacent the forward edge thereof in position at the forwardside of the work table W of the machine, as will be clear by referenceto Figs. 1 and 2. Cylinder unit TB is positioned with its axis generallyperpendicular or at an angle to the straight line path of reciprocationof the pawl carrier 6i] and includes, referring now to Fig. 14, theusual piston member 72 and piston rod or plunger "it, which latterextends outwardly from the inner end of the cylinder unit across andbelow the forwardly projected extension ma of bed it.

A bell crank unit 89 which includes a bored hub or body 8! having a longarm 82 extended radially from one end thereof and a short arm 88extended radially from the opposite end thereof, is provided foroperatively connecting the piston rod '53 of air cylinder unit H3 withthe pawl carrier ea. The arms 82 and 83 or bell crank W are positionedthereon in this instance at right angles to each other, that is, atlocations 90 apart around the axis of hub 81 This bell crank all ispivotally mounted on pivot screw 84 which is threaded at its upper endinto the under side of extension Ida of bed It in vertical positiondepending therefrom and being spaced forwardly of piston rod #3. Thepivot screw 8!; has a head S te at the lower end thereof and the bellbored hub 8! of bell crank 86) is rotatably mounted on pivot screw 8 inposition between head Bid and bed ill, with the long arm 82 extendedinwardly from the lower end of hub 8| and the short arm 83 extended fromthe upper end of hub Bl below and across the forward end of the slideway6! in bed extension ma and the pawl carrier til mounted in thatslideway.

The outer end of the piston rod 73 of air cylinder unit is is pivotallycoupled to the inner end of bell crank arm 82 by a coupling member orclevis 85. The extension Ilia of bed is through which the slideway 6!extends is provided with an elongated opening 85 therethrough which islongitudinally centered with the axis of slideway 5|, as will be clearby reference to Figs. 2 and 3. The forward end of the pawl carrier bar[it] is formed with an elongated opening or slot 8'5 therethroughdisposed transversely of the bar and located with its transverse centeraligned with the longitudinal axis of the bar. The short arm of bellcrank unit 39 is provided with a pivot pin receiving bore 83a thereinand a pivot pin at is mounted on the upper side of arm 83 with the lowerend thereof pivotally received and journalled in bore 83a. Pivot pin 80is carried on and rocks with arm 83 and extends upwardly therefromthrough slot 01' opening 85 in bed extension Ella. Pin 96 provides atits upper end a crank pin M which extends into and is slidably androtatably received in the transverse slot ill in the forward end ofcarrier bar 60.

With the pawl carrier bar 60 thus operatively coupled with the pistonrod it of air cylinder 19, displacement of the rod '53 outwardly of thecylinder unit, that is inwardly across the machine, will rock. the longarm 82 of hell crank 8% in a direction to swing the short arm 83inwardly or rearwardly relative to the machine to thereby slide the pawlcarrier 69 with pawl 55} thereon inwardly in. slideway all to perform anindexing stroke. Displacement of rod 13 inwardly in the air cylinderunit it wil1 effect rocking or the short arm 83 of bell crank 35outwardly and thereby slide or draw carrier bar 6Q with awl 55,forwardly on the return stroke or" the carrier bar and pawl preparatoryto the next indexing stroke.

Referring now to Fig. is, the air cylinder unit it is schematicallyshown as including inletoutlet ports is and 15 therein located adjacentopposite ends of the cylinder at opposite sides, respectively, of piston'62. Th air cylinder is controlled. by an air valve unit '58 which isschematically shown as including a valve plunger lea enclosed within acasing lESb. Valve plunger its is mounted for reciprocation under thecontrol of solenoids ll and '58 which have their respective armaturesconnected with opposite ends of the valve plunger. The solenoid I? whenenergized draws plunger 76a to the position shown in Fig. 14, in whichair under pressure is admitted by valve unit 16 to the outer side ofpiston F2 to displace the piston in a direction to actuate bell crank 88to move carrier 66 on its indexing stroke. The air under pressure insuch position of valve plunger 16a is supplied through pipe line Ma andinlet-outlet port 14. In such position of the valve plunger the cylinderat the opposite side of the piston l2 discharges to atmosphere throughport i5, pipeline 75a, valve plunger 76c and discharge outlet 751). Whensolenoid ll is deenergized and solenoid 78 is energized, the valveplunger "175a is drawn thereby to position at the opposite end of casinglfib to then supply air under pressure through pipe line 35a and port"l5, with port M and pipe line 74a then being placed in communicationwith discharge "l lh of valve unit 16 for release of pressure air toatmosphere. With the valve unit it so set the piston l2 is displacedoutwardly in the cylinder unit to thus actuate bell crank 80 in adirection to slide pawl carrier 60 outwardly on its return stroke.

The valve unit 76 is connected by a compressed air supply line l9 withany suitable source 79a of air under pressure. The solenoid llisconnected with the power lines "L and 18L by a circuit consisting ofcircuit lines l'la and TH). The solenoid TB is electrically connectedinto the power lines ML and 18L by the circuit lines 18a and Hill.

An open-top pocket or recess Hill is formed in bed ill (see Figs. 3 andl) adjacent the inner side of siideway 8i with this pocket also openinglaterally into the slideway. A micro switch It: is secured in positionin pocket H by removable clamps H52. Switch llll has a laterallyinwardly extended actuating member 193 which projects into the plane ofthe vertical forward 12 side edge of the pawl tail flange 54 when thepawl is'in position with the tooth thereof engaged in a notch 4| of theindex bar will be clear by reference to Fig. The location of switch H3!is such that with the carrier bar 58 and its pawl 59 at the end limit ofindexing stroke, the rear vertical edge E la of flange 54 is positionedin immediate proximity to but spaced to the rear of the inner end of theswitch actuating member ma. I

This controls automatically the operation of the carrier bar 50 on itsreturn strok from the posi tion assumed thereby at the completion of anindexing stroke. Switch llll is connected into the circuit line Nb ofthe energizing circuit to the air valve solenoid TI, and is normallyopen to break this circuit and maintain solenoid l'. de-energized.

A starter switch I is connected into the cult line it?) of the circuitto the solenoid l the air valve unit 15. This starter switch is of thenormally open type for operation to close momentarily the circuit tosolenoid '13. Starter switch I05 may be located at any convenient pointbut in the particular example hereof this switch N15 is mounted inposition read' y accessible to the operator at the forward side of thesupport structure of the copy table M, as shown in Fig. 1. This starterswitch @225 controls the indexing cycle of the indexing mecha-- nism forperforming automatically a ret stroke and an indexing stroke to therebyii fixture table 20 rearwardly on bed it from one position of index tothe next position of index.

With the fixture table it of the unit in an indexed position, such asshown in Fl. pawl carrier bar 66 is at the end of its ing stroke and thepawl 55 thereof is in position with its tooth 52 engaged in a notch libetween adjacent teeth 49 on the indexing bar as. When the operatordesires to index fixture table 2 inwardly to its next position of index,he operates starter switch l95 to thereby momen ari y close the circuitthrough solenoid ill to tarily energize that solenoid. Referring to 14,the energization of solenoid it will draw valve plunger lfia of valveunit "i to posi .on to discharge air under pressure at the inner side ofpiston '12 of air cylinder unit it, while placing the cylinder at theopposite oi the piston in communication with atmosphere. Plunger 13 isthus drawn outwardly through the action of bell crank unit 86 whichmoves pawl carrier 60 outwardly in slideway 6i with tl 56 rocking overthe next forwardly a: tooth 48 as the carrier bar moves forward asillustrated in Fig. 12. The pawl 59 is thus rocked about its pivot 5| toswing tail 53 and the tail flange 54 inwardly toward indexing bar toposition in which the tail flange 5e clears the inner end of the switchactuating member N3 of switch llll as bar Sll and pawl are movedforwardly. However, the instant that the pawl tooth 52 has cleared thattooth 463 over which it is forwardly riding, the tooth snaps in into thenext notch M with resulting st .11 ng of tail flange 54 outwardly intocontact th switch actuating member Iii-3, as shown in F l. 1.3. Thiscontact operates member 133 to effect instant closing of switch lei,with the result that the circuit to solenoid ll of the valve unit 16 isenergized to instantly reset the plunger 76a of valve unit 16 to reversethe operation of the cylinder unit 10 to cause plunger l3 thereof to beforced outwardly to thereby rock bell crank B0 in a direction to movethe pawl carrier 60 inwardly on its indexing stroke. Inward move ment ofpawl carrier 69 with tooth 52 of pawl 5i) engaged against surface 42 ofthe next inwardly adjacent tooth results in moving the fixture table 23inwardly to the next position of index as determined by the engagementof the inner end oi carrier bar Eli against the abutment surface I52 atthe inner end of the slideway 5!. The indexing mechanism and the fixturetable 23 then remain in this position of index until the next indexingcycle of return stroke and indexing stroke.

We provide for automatically, releasably locking the fixture table 2c inan indexed position through the medium of the gib 222. This automaticlocking is eiiected by forcing the gib 22 inwardly under pressure intoposition with the surface 2 Ia thereof clamped against the inclined,undercut surface I2a of slide I2 of bed It. Referring now to Fig. 8 ofthe drawings in connection with Fig. 2, a lock pin Ibis is reciprocallymounted in position extending through a bore Iilfiain fixture table 2t.Bore Ittc extends in this example from the left hand side edge of thetable 213 inwardly therethrough to the slideway 2i thereof. The innerend of lock pin I86 is loosely received in a recess Iss1) formed in theadjacent side of gib 22, such recess presenting at its inner end anabutment surface for engagement by the end of the lock pin. The lock pinI at is actuated and controlled by an air cylinder unit II}? which ismounted and supported from and which is movable as a unit with fixturetable 26. In this instance air cylinder III! is attached in position atthe under side of an outwardly extended bracket IEI'Ia attached inposition on the fixture table. If desired, as shown in Fig. 1, asuitable housing or casing I68 may be provided for enclosing this aircylinder unit Ifil'.

The air cylinder I31, referring now to Fig. 14, includes a piston IilI-Ireciprocal therein and attached to a piston rod H 3 which extendsaxially therefrom at the inner end thereof in axial alignment with thelock pin I96. Lock pin I86 is suitably connected and coupled at itsouter end to the inner end of the piston rod or plunger I I 0, so thatreciprocation of the latter eifects reciprocation of lock pin I35 in andthrough the bore IIIBa in the fixture table it. The piston IE8 is springloaded by an expansion spring unit III which is mounted on piston rodIII; between piston IE3 and the inner end of the cylinder unit. Springunit III acts to continuously bias the piston and piston rod outwardlyto thereby draw and maintain lock pin IIII moved outwardly from lookingposition clamping gib 22 against rail I2 of bed Iii. Air cylinder It?is, however, operated by air under pressure in the reverse or inwarddirection against the biasing forces of spring I II to thereby force thelock pin Iilt to clamp gib 22 against rail I2 and thereby securely loci:fixture table 20 against displacement.

The air operation of cylinder II]? is through the medium of an air valveunit I I2 which includes a casing HZG; within which there isreciprocally mounted a valve plunger II2b having one end thereofconnected to the armature of a solenoid lid. The outer end of aircylinder It! is connected through an inlet-outlet port H5 with the airvalve M2 by pipe line lid. The air valve IIZ receives compressed airfrom the source 1% through pipe line III. The air valve II 2 asschematically shown in Fig. 14, is in position placing air cylinder Iill in communication for discharge to atmosphere through discharge I I8.The valve plunger H22) is continuously spring biased to this positionwhen the solenoid I It is deenergized, by a contraction spring H9. Whensolenoid Ilt is energized, valve plunger II 2b is displaced against theforces of spring lit to a position in which air under pressure fiowsthrough valve unit I I2 from supply line I I? to the cylinder IEII tothereby displace piston I09 inwardly and force lock pin I06 inwardly toclamp gib 22 into position locking fixture table 20 to bed III.

The automatic operation of the air cylinder It? to effect locking andrelease of fixture table 26 to and from bed III, is under the control ofa microswitch I28 which is mounted in an open top pocket or recess I2Iformed in bed I0 between guide rails I2 and I4. Switch I20 includes theswitch actuating member I22 which extends horizontally forwardlytherefrom through an opening 62a so that the end of member I22 projectsthrough abutment surface 62 at the end of slideway 6| in line with andfor engagement by the inner end of the slide carrier bar Iiil. Theswitch I28 is of the normally open type and is closed by inwarddisplacement of the actuating member I22, the switch being spring loadedto restore to normal open position upon release therefrom of inwardlyacting forces applied thereto.

The solenoid I It for controlling the valve unit I I2 of air cylinder I67 is connected into the power lines TIL and ML by the circuit comprisedof the circuit lines lite and I I417, as will be clear by thediagrammatic disclosures of Fig. 14. The normally open microswitch I2!)is in this instance connected in the circuit line I Mb to the solenoid II4 so as to energize that solenoid when the switch is closed and to openthe circuit and deenergize solenoid II I when the switch is open.

The switch It'd is operated to closed position closing the circuitthrough and energizing solenoid IHI by the engagement of the inner endof carrier bar 66 with the switch actuating member I22 at the instant ofengagement of the inner end of the carrier bar against the abutmentsurface I52 which determines the end limit of the indexing stroke of thecarrier bar. The instant that the switch I26 is closed the solenoid II Iis energized and the valve plunger IIZa is displaced to position openingthe cylinder at the outer side of piston I99 to the compressed airsupply line I If, so that compressed air i supplied to cylinder Iii?through the valve unit II2, pipe lit and port I Ill. The air pressurethus established in cylinder Iii? forces the piston IE9 and the pistonrod lie inwardly to thereby force the lock pin lot to clamp gib 22 inposition locking fixture table 29 against displacement. The gib 22 willremain in locked position held under pressure by the air cylinder unitIIi'I, until the next return stroke of the carrier bar 6E3.

When the carrier bar 5t starts on its return stroke it does so of courseindependently of the locked fixture table 2! and as it moves outwardlyin slideway IiI it disengages from and releases switch. actuating memberI22 so that the switch IZd then instantly restores to its normal openposition. Opening of switch I26 results in deenergization of solenoid H4and the spring Iii! then takes over control of valve plunger I IZc andresets that plunger to cut on" compressed air supply to the cylinderunit IIII' while placting that cylinder unit in communication withatmosphere. The spring III then takes over and forces piston weoutwardly to release locking pin Is from clamping engagement with thegib 22 thus releas- .15 ing fixture table in preparation for the nextindexing step thereof.

We have thus provided for indexing the work holding fixture table 29step by step through successive indexing positions under the control ofthe operator, with each indexing cycle from one indexing position to thenext being automatic but initiated only at the will of the operatorthrough the starter switch I85. And we have provided also for locking ofthe fixture table 2!] automatically upon the instant that such tablereaches an indexed position, with maintenance of such locking untilrelease thereof automatically by the initial movement of the indexingmechanism on its return stroke. The fixture table 26 having removablymounted thereon a selected indexing bar, such as the bar so or the bar3% of this example, is positioned for starting at the forward side ofbed ID as shown in Fig. 2 at the first position of index. In thisstarting position the switch 28 is closed by engagement of the inner endof the carrier bar 60 with the switch actuating member I22, and thelocking mechanism is thus in locked position securely holding the tableagainst displacement from its position of the index. When the operatorwishes to index the xture table 2i! to its next position of indexinwardly across bed I9, he merely momentarily actuates starter switchI85 and thereby initiates the automatic indexing cycle during which thelocking mechanism is released and the carrier bar 68 and pawl 5'9perform a return stroke and an indexing stroke to move table 26 inwardlya distance equal to the spacing between the adjacent teeth of theindexing bar then engaged by the pawl. Irrespective of tooth spacing onthe particular indexing bar mounted on table 29, the indexing mechanismwill automatically adjust the return stroke of carrier bar 56 and pawl59 to the particular tooth spacing of that bar. The operator maycontinue to efiect step by step indexing rearwardly of fixture table 26through the positions of index as determined by the indexing bar bymerely operating starter switch 5% whenever he desires to index thetable from one position to the next. Such indexing may be continueduntil pawl 52 reaches the last notch of the indexing bar with the tablethen at its limit of movement rearwardly. Such position for the bar 36and fixture table being shown in Fig. l. The fixture table 28 maythereafter be slid forwardly to the starting position for another cycleof rearward indexing. In order to permit of the return of fixture table28 to its starting position at the forward side of bed I it is necessaryto disengage pawl 50 from the teeth of the indexing bar and maintain thepawl so disengaged while the table is being slid forwardly to itsstarting position.

We have provided a form of pawl disengaging mechanism by which fixturetable 26 may be released for movement forwardly on bed HI to a startingposition. Such mechanism in this example comprises a hand lever i3)which is mounted in horizontally disposed position at the forward sideof bed It by a bracket I3! which mounts a vertical pivot pin I32 onwhich lever $36 is rotatably mounted for rocking thereof toward and frombed Ii]. A cable I33 connects the inner end of lever I39 with theforward end or pawl 5%, this cable being extended rearwardly along bedill to a pulley I34 around which it is extended to the forward end ofthe pawl to which the cable is attached. By swinging the outer end oflever I inwardly toward bed III cable I33 will rock pawl about its pivot5! to a position with the pawl tooth 52 disengaged from and clear of theteeth of the indexing bar mounted on din ture table 29. Pawl 50 isrocked to this engaged position against the forces of its biasing springand by holding lever I30 in its inwardly swung position with the pawldisengaged, the operator may manually slide fixture table 28 forwardlyto its starting position. After the table is brought to startingposition the operator merely releases lever I39 so as to permit thespring 55 to restore the pawl to indexing position engaged in theinnermost notch of the indexing bar, such as the notch 4| of the bar 30as shown in Fig. 2.

In order to prevent displacement of the fixture table 28 too farrearwardly, or completely from bed I0, we have provided a stop bracketor plate attached .to the rear vertical edge wall or" bed is. This stopplate I35 extends vertically upwardly above the plane of the top surfaceof bed If: in position for engagement by the rear vertical wall offixture table 29 and thereby limits rearward movement of the table.

Preferably a position indicator is provided by which the operator mayvisually check against a sample or facsimile template to determine theworking position of the particular design being engraved at any time ona work piece, such as the work pieces 1'1, of this example. An exampleform of such an indicator as illustrated herein, is con: prised by abracket member I49 in the form or" an angle bar secured along one sideedge of ure table 20, in this instance the right hand edge, with theflange Mi of bracket 523 being horizontally disposed along and extendingoutwardly from the fixture table. An indicator I42 is attached in fixedposition on the right hand edge wall of bed I0 and extends outwardlytherefrom below bracket MS with the upper portion of this indicatorbeing bent or extended inwardly over the upper side of flange MI toprovide the pointer I43. A template Mt having formed thereon an exactreplica of the series of designs and the spacings therebetween to beformed on v the work pieces R, is removably mounted in position on theupper side of bracket flange I42 with the first of the series of designspositioned under pointer I43 when the fixture table as is set in itsforward, starting position. as shown in Fig. 2. Thus as the table 26 isindexed rearwardly, the template M4 is correspondingly moved tosuccessively bring the designs thereon under the pointer I43 to thusindicate visually to the openator the position of a work piece relativeto the cutting tool.

In the example herein illustrated and described the power means foractuating the indexing mechanism and the power means for actuating thefixture table locking mechanism are each of the compressed air operatedcylinder and piston type, but it is not intended by such examples tolimit our invention to such types, as other air operated types may beutilized, as well as power units employing other actuating fluids thancompressed air. Similarly, in its broader aspects our invention is notlimited to the use of pressure fluid actuated power means, as othermotive power forms capable of control by the indexing mechanism and byan operator in the combination and manner as required by our inventionmay be substituted.

It will also be evident that various other changes, variations,modifications, substitutions, eliminations and additions may be resortedto Without departing from the broad spirit and scope of our inventionand hence we do not intend or desire to limit our invention in allrespects to the exact and specific disclosures of the example hereinpresent, except as may be required by specific intended limitationsthereto appearing in any of the claims hereto appended.

What we claim is:

1. In an indexing work fixture, in combination; a support structure; atable member movably mounted on said support structure for and beingconstrained to movements in either direction along a straight line path;an indexing bar removably attached to said table member in positionparallel with the straight line path of movements of the table member;said indexing bar being provided along one side thereof with a series ofindexing teeth spaced apart distances corresponding to the distances ofspacing, respectively, between successive positions of index to whichsaid table member is to be moved in one direction along said straightline path; indexing mechanism mounted on said support structure andincluding, a carrier member mounted for reciprocation along a straightline path parallel with the path of movements of said table member; anda pawl member pivotally mounted on said carrier member and being adaptedto engage a tooth of said index bar on the indexing stroke in onedirection of movement of said carrier member and to be moved intoengagement with an adjacent tooth of said indexing bar on the returnstroke of said carrier member in the reverse direction; operatorcontrolled power means for operating said indexing mechanism; and meansadapted to be operated automatically by said pawl member upon engagementof said pawl member on its return stroke with an adjacent tooth toarrest the movement of said indexing mechanism on its return stroke andto initiate automatically operation of said mechanism on an indexingstroke.

2. In an indexing work fixture, in combination; a support structureprovided with spaced guide rails thereon; a table member provided with aslideway therein, said table member being mounted on said suportstructure with said guide rails being slidably received in said slidewayfor movements of said table member thereon; indexing mechanism on saidsupport structure adapted to engage said table member for sliding thelatter in one direction on said guide rails step by step to successivepositions of index; a locking member movably mounted on and carried bysaid table member and being positioned within said slideway formovements to and from looking position engaged against one of said guiderails to releasably lock said table member against movement; operatingmeans on and movable as a unit with said table member for moving saidlocking member to locked position; and means adapted to be controlled bysaid indexing mechanism for actuation thereby when said table member isin a position of index for causing actuation of said locking memberoperating means.

3. In the combination as defined in claim 2 above; the locking memberoperating means being comprised by an actuating unit of the air operatedtype; operative connection between said unit and said locking member; asolenoid actuated air valve adapted to controloperation of said unit; anelectrical circuit for the solenoid of said valve unit; a normally opencontrol switch in said circuit; and said indexing mechanism beingadapted to engage said switch to close said circuit when said tablemember reaches a position of index.

4. In an indexing work fixture in combination; a support structureprovided with spaced guide rails thereon; a table member provided with aslideway therein, said table member being adapted to be mounted on saidsupport structure with said guide rails being slidably received in saidslideway for movements of said table memher in either direction thereonconstrained to a straight line path thereby; an indexing bar removablyattached in position at the inner side of said table member disposedlongitudinally within said slideway between said guide rails; saidindexing bar being provided along the inner side thereof with a seriesof spaced indexing teeth; a carrier bar reciprocally mounted in saidsupport structure between said guide rails beneath said indexing bar onsaid table member; an indexing pawl pivotally mounted on said carrierbar at the inner side of said indexing bar for indexing engagement withthe indexing teeth of said bar; and means on said support structureadapted for operation to reciprocate said carrier bar and pawl throughan indexing stroke in one direction and a return stroke in the reversedirection.

5. In the combination as defined in claim 4 above; said indexing pawlbeing pivotally mounted for movements toward and from the indexing teethof said indexing bar; said carrier bar reciprocating means including anair cylinder unit and a solenoid actuated control valve connectedtherewith; said air cylinder unit including a reciprocally mountedpiston rod operatively coupled with said carrier bar and being adaptedon reciprocation in one direction to move said bar on an indexing strokeand on reciprocation in the reverse direction to move said bar on areturn stroke; electrical circuits to said solenoid control valve; and acontrol switch connected in said circuits and being mounted on saidsupport structure in position for actuation by said pawl as the latteris moved with said carrier bar on a return stroke of the said bar tocause said cylinder unit to reciprocate said carrier bar in the reversedirection on an indexing stroke.

6. In an indexing work fixture, in combination; a support structure; atable member slidably mounted on said support structure for movementsthereon in either direction along a straight line path; an indexing barattached on said table member and being provided along one side thereofwith a series of spaced indexing teeth; a carrier bar reciprocallymounted on said support structure in position beneath said indexing baron said table member; an indexing pawl pivotally mounted on andreciprocal with said carrier bar; said pawl being mounted in positionadjacent and being rockable to and from indexing engagement with theteeth on said bar; means on said support structure for reciprocatingsaid carrier bar and pawl in one direction to perform an indexing strokethereof and in the opposite direction to perform a return stroke;control means adapted to be engaged with and actuated by said pawl atthe end of the return stroke of said carrier bar to cause reversal ofoperation of said reciprocating means to perform an indexing stroke ofsaid carrier and pawl; and an operator actuable con trol means forinitiating operation of said carrier bar reciprocating means to movesaid bar and pawl on a return stroke.

7. In an indexing work fixture, in combination;

a support structure; a table member movably mounted on said supportstructure for movements to successive positions of index thereon; agroove formed in the under side of said table membe parallel with thepath of movements of the said table member on said supporting structure;and an indexing bar having an attaching rib thereon adapted to beslidably received in said table member groove for removably mountingsaid indexing bar in position on said table; and means on said table forreleasably attaching said indexing bar in mounted position.

8. In an indexing work fixture, in combination; a support structure; atable member slidably mounted on said support structure for movements ineither direction along and constrained to a straight line path; indexingmechanism mounted on said support structure and including areciprocatory member for engaging said table member on an indexingstroke thereof to move table member from one position to the nextposition of index, said reciprocatory member on the return strokethereof in the reverse direction being adapted to be positioned forengaging said table member on the next indexing stroke; an air cylinderunit mounted on said support structure, said air cylinder unitincluding, a reciprocating piston rod operatively connected with saidreciprocatory member of said indexing mechanisms for reciprocating saidmember; an air control valve connected with said cylincie' unit andbeing operable to one position for effecting reciprc cation of saidpiston rod in one direction to another position for efieotingreciprocation of said rod in the reverse direction; a solenoid foractuating said valve unit to said one position; a second solenoid foractuating said valve unit to said other position; an electrical circuitfor said first mentioned solenoid; an electrical circuit for said secondmentioned solenoid; a normally ope switch in said first solenoid circuitadapted to actuated by an operator to close said circuit; a normallyopen switch in said second so'ienoid circuit adapted to be actuated toclose said second solenoid to reset said valve unit to position forreversing said cylinder unit, and said switch in said second solenoidcircuit being adapted to be actuated automatically by said indexingmechanism at the end of its movement on a return stroke thereof.

9. In an indexing work fixture, in combination; a support structure; atable member movably mounted thereon; an indexing bar removably se curedon said table member, said bar having a series of indexing teeth thereonwith successive teeth of said series being spaced apart distancescorresponding to the distances of spacing between successive positionsor" index, respectively, of said table member; a carrier memberreciprocally mounted on said support structure; an indexing pawlpivotally mounted on said car rier member and being adapted for indexingengagement with successive teeth or" said indexing bar; variable stroke,reversible power means connected with said carrier member forreciprocating said member through selected predetermined length indexingand return strokes; normally in- 7 active control means connected withsaid power member during a return stroke thereof when the pawl memberarrives in position in indexing engagement with the next adjacent toothon said indexing bar.

10. In an indexing work fixture, in combination; a support structure; atable member movably mounted on said support structure; indexingmechanism mounted on said support structure and being adapted to movesaid ta le member progressively step by step in one direction tosuccessive positions of index spaced varying distances apart; of aselected series of positions of index; an indexing bar removablyattached to said table member and having thereon a series of indexingteeth spaced apart therealong distances corresponding to the distancesof spacing between the successive positions of index, respectively, ofthe selected series of index positions through which said table memberis to be moved; said indexing mechanism including an actuating memberoperable thereby through an indexing stroke and a return stroke andbeing adapted to engage a tooth of said indexing bar on each indexingstroke thereof; and means operativeiy associated with and adapted to becontrolled by said actuating member on each return stroke thereoftocause said indexing mechanism to arrest automatically the return strokeof the actuating member when the latter has been moved to a position ofindexing engagement with the next adjacent tooth of said indexing bar.

11. In an indexing work fixture, in combination; a support structure; atable member mounted so said support structure for movements tosuccessive positions of index thereon; variable stroke indexingmechanism mounted on said support structure and being adapted to effectindexing movements of said table member progressively step by step inone direction to successive positions of index spaced varying distancesapart; an indexing bar removably mounted on said table member and beingformed to provide a series of indexing teeth spaced apart therealongdistances corresponding to the distances of spacing between thesuccessive positions of index, respectively, through which said tablemember is to be moved; power means for operating said variable strokeindexing mechanism; said indexing mechanism including an indexing memberoperable thereby through a variable indexing stroke in engagement withone of the teeth on said indexing bar and through a variable returnstroke for engagement with the next adjacent tooth of said bar; andcontrol means operatively connected with said power means and beingadapted to be actuated by said indexing member when said indexing memberreaches a position on its return stroke in indexing engagement with anadjacent tooth to cause such power means to arrest the return stroke andto initiate automatically an indexing stroke of the indexing member ofsaid indexing mechanism.

12. In an indexing work fixture, in combination; a support structure; atable member movably mounted on said support structure; indexingmechanism mounted on said support structure and including an indexingmember operable through variable indexing and return strokes adapted tobe engaged with said table member to move the table member progressivelyin one direction step by step to successive positions of index spacedvarying distances apart; power means connected with said indexingmechanism and being adapted for selective operation to selectivelyactuate said indexing member throu h variable strokes thereof; controlmeans operatively connected with said power means for causing operationof said power means to actuate said indexing member; and means on saidwork table adapted to operatively engage said control means to causeoperationof said power means to arrest a return stroke of said indexingmember and initiate an indexing stroke thereof when said indexing memberhas moved on its return stroke a distance equal to the spacing betweenthe position of index to which said table member has been moved and thenext successive position of index.

13. In an indexing work fixture, in combina tion; a support structure atable member mounted on said support structure for movementsprogressively in one direction to successive positions of index thereon;indexing mechanism adapted for operation to move said work tableprogressively step by step to successive positions of index; saidindexing mechanism being mounted on said support structure and includingan indexing pawl operable through an indexing stroke; an indexing barremovably attached to said Work table and having a series of indexingteeth spaced apart thereon adapted to be engaged successively by saidindexing pawl to move said work table from one position of in dex to thenext position of index; locking mechanism operable to and from positionreleasably locking said work table in each position of index; andcontrol means operatively associated with said locking mechanism adaptedto be actuated automatically by said indexing mechanism when said tablemember reaches a point of index to cause operation of said lockingmechanism to releasably lock the table in such position of index.

14. In the combination as defined in claim 11 above; said power meansbeing comprised by an air cylinder unit including a piston rod adaptedto be reciprocated thereby; said piston rod being operatively coupledwith said indexing mechanism for efiecting operation of said indexingmechanism through an indexing stroke or a return stroke; a solenoidactuated air control valve connected with said air cylinder unit;electrical circuits for said control valve; and said control means beingcomprised by switches connected in said electrical circuits, one of saidswitches being adapted for operator actuation and the other of saidswitches being adapted for actuation automatically by said indexingmechanism on a return stroke thereof.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 512,829 Hunter Jan. 16, 1894 1,110,751 Doner Sept. 15, 19141,175,195 Thomas Mar. 14, 1916 2,005,696 Groton et al June 18, 19352,090,649 Tetreault Aug. 24, 1937 2,249,989 Harley July 22, 19412,371,675 Cherry et al Mar. 20, 1945 FOREIGN PATENTS Number Country Date600,150 Great Britain Apr. 1, 1948

